package com.jee.support.thread;import java.util.concurrent.locks.*;public class MutexEvenGenerator extends IntGenerator {	private int currentEvenValue = 0;	private Lock lock = new ReentrantLock();	public int next() {		lock.lock();		try {			++currentEvenValue;			Thread.yield(); // Cause failure faster			++currentEvenValue;			return currentEvenValue;		} finally {			lock.unlock();		}	}	public static void main(String[] args) {		EvenChecker.test(new MutexEvenGenerator());	}}